The rovers’ view of Mars

The view from the top of Mont Mercou
Click for higher resolution. For original images, go here and here.

Some cool images to savor from Mars! Above is a panorama from Curiosity, created by me from two images taken by the rover’s left navigation camera today, April 18, 2021. The view is southwest towards the canyon regions where Curiosity will be heading in the coming months. Note the roughness of the ground. Travel is going to be tricky from here on out.

The photo was taken from the top of Mont Mercou, the 20-foot high outcrop that the rover spent several weeks studying at the cliff’s base. The Curiosity science team is presently preparing to drill into the bedrock at the top.

Ingenuity on the floor of Jezero Crater
Click for full image.

The photo to the right, reduced to post here, was taken by Perseverance on April 13, 2021, and looks west across the floor of Jezero crater. The high mountains in the distance are the crater’s rim. The low and much closer hill is the delta that is the rover’s primary geological target.

In the center of the picture is the helicopter Ingenuity. You can also see the tracks of Perseverance’s wheels just below it.

This will be the rover’s vantage point when Ingenuity attempts its first test flight in the early morning hours of April 19, 2021. The helicopter will head to the right once it lifts off.

Clouds over Gale Crater

Clouds over Gale Crater
Click for full image.

Cool image time! In today’s download of new images from Curiosity was a large number looking at the sky. by one of the rover’s navigation cameras. As noted in the science team’s most recent update, their aim was to “watch for clouds in the sky at twilight.”

They were apparently very successful. The picture to the right, reduced to post here, is one example. The other pictures show these clouds and other clouds as they change over time.

I don’t have much more to add, other than to say it is quite breath-taking to be able to sit here on Earth and routinely gaze at the weather on Mars.

UPDATE: I do have one more thing to say. If you have any skills at programming and want to figure out how to process the raw images from Curiosity and Perseverance to bring out their color, you might find the video at this link of interest: How Can You Color Process Mars Rover’s Images In DaVinci Resolve?

I am not a computer programming geek, so some of its details went over my head. Nonetheless, it opened a window into the photo-engineering used to turn the rovers’ black-and-white digital data into color.

Hat tip to Patrick Inhofer, who calls himself the photon wrangler at MixingLight.com.

Curiosity faces the mountains

A cropped section from Perseverance's 1st panorama
A cropped section from Perserverance’s 1st panorama.
Click for full image.

Though the present excitement over the spectacular images and sounds coming down from Perseverance is certainly warranted, what must be understood is that this rover is presently only at the beginning of its journey, and is thus sitting on relatively boring terrain, from a merely visual perspective. The scientists might be excited, but to the general public, all we really are seeing is a flat dusty desert with some scattered rocks on the floor. In the far distance can be seen some hills and mountains (Jezero Crater’s rim), but they are very far away.

Curiosity, which the press and the public has largely forgotten about, is actually just beginning what will likely be the most breath-taking part of its journey. As I noted in my last rover update last week, Curiosity is now at the very base of Mount Sharp, and is about to enter the mountain’s canyons and initial slopes. For its past eight-plus years of roving it has been on the flat floor of Gale Crater, followed by some weaving among the smallest foothills of Mount Sharp. The views have been intriguing and exciting from a research perspective, but hardly breath-taking from a picture-taking point of view.

That is now changing. The picture below, taken by Curiosity just this week, gives us a taste of what is to come.
» Read more

Rover update: Panorama from Curiosity; Perseverance unwinds

Summary: Curiosity has crept to the foot of Mt Sharp at last, while Perseverance checks out its equipment.

Curiosity

Curiosity panorama Sol 3049
Click for full resolution.

Overview map

This rover update will be short but very sweet. While the press and public has been oo’ing and ah’ing over the first panorama from Perseverance, Curiosity yesterday produced its own panorama above showing the looming cliffs of Mt. Sharp, now only a short distance away. The original images can be found here, here, here, and here.

The overview map to the right, from the “Where is Curiosity?” webpage, shows the rover’s location, with the yellow lines roughly indicating the view afforded by the panorama above. If you compare this panorama with the one I posted in my previous rover update on February 12, 2021, you can get a sense of how far the rover has traveled in just the past two weeks. It now sits near the end of the red dotted line pointing at the mountain, right next to what had been a distant cliff and now is only a short distance to the rover’s right.

Somewhere on the mountain slopes ahead scientists have spotted in orbiter images recurring slope lineae, seasonal streaks on slopes that appear in the spring and fade as they year passes. As Curiosity arrives at the next geological layer a short distance ahead at the base of these cliffs (dubbed the sulfate unit), it will spend probably several months studying both that sulfate unit as well as those lineae. Expect the rover to drill a few holes for samples as it watches to see any changes that might occur on that lineae.

Now, on to Perseverance!
» Read more

Scientists: Gale Crater never had flowing surface water and was always cold

The uncertainty of science: According to a new analysis of the data from Curiosity and Martian orbiters, scientists now propose that the climate in Gale Crater was never warm, but ranged from Icelandic conditions to far colder.

More importantly, the data suggests that none of chemistry there that required the presence of water was formed by fluvial processes, or flowing water. From the abstract:

We show that the geochemistry and mineralogy of most of the fine‐grained sedimentary rocks in Gale crater display first order similarities with sediments generated in climates that resemble those of present‐day Iceland, while other parts of the stratigraphy indicate even colder baseline climate conditions. None of the lithologies examined at Gale crater resemble fluvial sediments or weathering profiles from warm (temperate to tropical) terrestrial climates. [emphasis mine]

As must be repeated, the mineralogy found by Curiosity points to the presence of water once in Gale Crater, now gone. The initial assumption has always been that this water must have been liquid, as found on Earth. This new research is noting that the conditions show little evidence that liquid water ever existed, but was instead held in frozen lakes and glaciers.

In the coming years I think we are going to learn a lot about the glaciers and ice on Mars, both past and present, and how they reshaped Mars in ways that are alien to processes found on Earth.

Curiosity checks out its wheels

One wheel on Curiosity, as seen in July 2020 and January 2021
For full resolution images, go here and here for the
top image, and here and here for the bottom image.

Having finished a two week look at a sea of sand, Curiosity’ science team has resumed its journey east towards the higher slopes of Mount Sharp.

Before they started out however, they decided to aim the rover’s high resolution mast camera at Curiosity’s wheels to see how they are faring and whether any of the damage that occurred in the early days of the mission has worsened. The photo on the right compares what was seen this week with the damage on the same wheel as seen in July 2020. This is also the same wheel I have posted images of since September 2017.

Not only does there appear to be no appreciable new damage to this wheel in the six months since July, remarkably, a comparison between today’s image and the photo from September 2017, shows little change as well.

In the more than three years since that 2017 photo, Curiosity has crossed Vera Rubin Ridge, crossed the clay unit, climbed up the next ridge to take a look at the incredibly rough terrain of the Greenheugh Pedimont, and then continued across the clay unit on its way to higher and possibly more challenging terrain.

In all those travels it appears this particular wheel has fared rather nicely, accumulating in at least this part little new damage. This bodes well for the rover’s future, as the wheels have been a concern since Curiosity’s first two years on Mars, when engineers found they were experiencing more damage than expected. The travel techniques they have adopted since to protect the wheels appear to be working.

Published results from Curiosity as it traversed Vera Rubin Ridge

The science results from American Mars rover Curiosity during its traverse of Vera Rubin Ridge at the base of Mount Sharp in Gale Crater have now been released to the public.

This link takes you to the overview paper, available online for free. The abstract notes the key finding, which confirms previously released research:

We conclude Vera Rubin ridge formed because groundwater recrystallized and hardened the rocks that now make up the ridge. Wind subsequently sculpted and eroded Mount Sharp, leaving the harder ridge rocks standing because they resisted erosion compared with surrounding rocks. The implication of these results is that liquid water was present at Mount Sharp for a very long time, not only when the crater held a lake but also much later, likely as groundwater.

The fundamental geological mystery of Mars remains. The evidence strongly says that liquid water must have existed for long periods on the surface of Mars. At the same time, other evidence strongly says that the climate and atmosphere of Mars has never been warm enough or thick enough to allow for liquid water on the planet’s surface.

So far, no global model proposed by any theorist that allows liquid water in the past on Mars has been accepted with any enthusiasm by the planetary community. While possible, the models carry too many assumptions and are based on what is presently far too limited data. We simply do not yet know enough about Mars and its past history to explain this conundrum.

The paper also outlines a number of models for allowing liquid water in the localized area of Gale Crater alone. As with the global models, none fits all the facts, or is entirely satisfactory for explaining the data.

Regardless, the results from Vera Rubin Ridge confirm once again that enough liquid water once did exist on Mars to have allowed it to be habitable for life, even if we have so far found no evidence of any past life.

Curiosity data suggests the occurrence of mega floods in Gale Crater

The uncertainty of science: Using Curiosity data a team of scientists are now suggesting that some of the features the rover has seen were created during mega flood within Gale Crater, and this data also requires a rethinking of the present theories of the crater’s geological history.

This case includes the occurrence of giant wave-shaped features in sedimentary layers of Gale crater, often called “megaripples” or antidunes that are about 30-feet high and spaced about 450 feet apart, according to lead author Ezat Heydari, a professor of physics at Jackson State University.

The antidunes are indicative of flowing megafloods at the bottom of Mars’ Gale Crater about 4 billion years ago, which are identical to the features formed by melting ice on Earth about 2 million years ago, Heydari said.

The most likely cause of the Mars flooding was the melting of ice from heat generated by a large impact, which released carbon dioxide and methane from the planet’s frozen reservoirs. The water vapor and release of gases combined to produce a short period of warm and wet conditions on the red planet.

The press release above focuses on the catastrophic floods, but the research paper itself is really much more focused on the need to rethink present hypotheses for explaining the observed geology in Gale Crater. This report notes that they are finding patches of material that could not have been laid down as seen, based on those past theories, and proposes the catastrophic flood event as a possible solution.

In reading the paper however it is evident that even this new hypothesis is based on a limited amount of data, and thus can have holes punched in it as well. This is not to say that the paper is invalid, only that it must be taken with some skepticism. The data being obtained at Gale Crater simply incomplete. Curiosity is following only one path, and has not even left the foothills of Mount Sharp. In order to gain a wider and fuller understanding geologists need to study the entire crater floor, as well as the geology on the mountain.

Rover update: Curiosity on the move again

After spending more than three months at a single site, drilling three different holes in the same rock, Curiosity is finally on the move again, heading east and uphill toward Mt. Sharp. Yutu-2 meanwhile continues its very slow journey on the far side of the Moon. And the new rovers are halfway to Mars.

Drill holes at Mary Anning site in Gale Crater
Click for full image.

Curiosity

The image to the right, cropped and annotated to post here, shows the three drill holes that scientists had Curiosity drill in this one pavement rock, dubbed Mary Anning and located in the clay unit within Gale Crater on Mars. As I noted in my last update on July 22, 2020, the rover’s science team had made a specific detour in their planned route up Mt. Sharp in order to find this one last place to drill in this geological unit.

Though they have been very quiet about their results, apparently what they found in this one pavement rock was important enough that it required three drill holes. In addition, samples from the second hole were subjected to two of Curiosity’s limited supply of wet chemistry experiments. From the science team’s August 28, 2020 update:
» Read more

Curiosity captures a dust devil

During its recent and last several-week-long drilling effort in the clay unit in Gale Crater, the rover Curiosity was also able to luckily capture the passing of a nearby dust devil.

It’s almost summer in Gale crater, which puts us in a period of strong surface heating that lasts from early spring through mid-summer. Stronger surface heating tends to produce stronger convection and convective vortices, which consist of fast winds whipping around low pressure cores. If those vortices are strong enough, they can raise dust from the surface and become visible as “dust devils” that we can image with our cameras. The animated GIF shows a dust devil movie we took with Navcam on Sol 2847, covering a period of about five minutes. We often have to process these images, by enhancing what’s changed between them, before dust devils clearly show up. But this dust devil was so impressive that – if you look closely! – you can just see it moving to the right, at the border between the darker and lighter slopes, even in the raw images.

I have embedded the movie below the fold. The dust devil looks like a ghostly white tower moving from the left to the right just above the darkest band of landscape cutting across the middle of the image.
» Read more

Rover update: Curiosity pauses to drill

Curiosity's entire journey so far in Gale Crater

Overview map of Curiosity's recent travels

The artist’s oblique drawing above, as well as the map to the right, provide some context as to Curiosity’s present location and its entire journey in Gale Crater. For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater. For all rover updates since then through May 2020, go here.

Since my last update on July 7, 2020, Curiosity has quickly moved a considerable distance to the east, as planned, skirting the large sand field to the south in its journey to the best path upward onto Mt. Sharp. The science team however has detoured away from their planned route, shown in red on the map, heading downhill a bit in order to find one last good location in the clay unit to drill. They are at that location now and are presently scouting for the best drilling spot.

About a week ago, before heading downhill, they had stopped to take a set of new images of Curiosity’s wheels. » Read more

Rover update: Curiosity’s future journey

Mount Sharp, with Curiosity's future travels
Click for full image.

[For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater. For the updates in 2018 go here. For a full list of updates before February 8, 2018, go here.]

Today the science team of Curiosity issued a press release outlining their travel plans for the rover over the next year. In conjunction, they also released a mosaic of 116 images taken by the rover showing that route, a reduced in resolution version shown above.

The rover’s next stop is a part of the mountain called the “sulfate-bearing unit.” Sulfates, like gypsum and Epsom salts, usually form around water as it evaporates, and they are yet another clue to how the climate and prospects for life changed nearly 3 billion years ago.

But between the rover and those sulfates lies a vast patch of sand that Curiosity must drive around to avoid getting stuck. Hence the mile-long road trip: Rover planners, who are commanding Curiosity from home rather than their offices at NASA’s Jet Propulsion Laboratory in Southern California, expect to reach the area in early fall, although the science team could decide to stop along the way to drill a sample or study any surprises they come across.

Overview map sol 2804 of Curiosity's route

This journey actually began in late May, at about the time of my last rover update. The overview map to the right shows in red their approximate planned route to avoid that large dune field to the south. The meandering yellow line indicates Curiosity’s actual route. The straight yellow lines indicates I think the area covered by the mosaic above. As you can see, since the end of May they have quickly returned to their planned route. Note also that the dune field extends about twice the distance beyond the eastern edge of this overview map.

The next big goal when they reach that sulfate-bearing unit will be to not only study it but to also study a recurring slope lineae on the slopes of that unit, a streak that darkens and lightens seasonally that might be caused by seeping brine from below. Because the sulfate unit and the linneae are both major geological goals, they are going to be moving fast to get there. I am sure they will periodically stop to do geology, but I think the travel will be, as it has been for the past month, quick-paced.

Once the rover gets to the sulfate unit, Curiosity will at last have actually reached the base of Mount Sharp. Up until now it has been traveling first in the surrounding plains, then in the mountain’s foothills. The terrain will get much rougher and be far more spectacular, as Curiosity will be entering canyons as it begins to climb the mountain itself.

Help scientists plan Curiosity’s future travels

The Curiosity science team is asking the help of ordinary citizens in improving the software it uses to plan Curiosity’s future travels.

Using the online tool AI4Mars to label terrain features in pictures downloaded from the Red Planet, you can train an artificial intelligence algorithm to automatically read the landscape.

Is that a big rock to the left? Could it be sand? Or maybe it’s nice, flat bedrock. AI4Mars, which is hosted on the citizen science website Zooniverse, lets you draw boundaries around terrain and choose one of four labels. Those labels are key to sharpening the Martian terrain-classification algorithm called SPOC (Soil Property and Object Classification).

The goal is not to have citizens plan the rover’s route, but to use their judgments to refine the software that the scientists and engineers use to plan the route. This refinement will also be applicable to Perseverance when it gets to Jezero Crater in February 2021.

Rover update: The state of Curiosity’s wheels

[For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater. For the updates in 2018 go here. For a full list of updates before February 8, 2018, go here.]

In my last rover update (April 16, 2020), I posted some new images taken of Curiosity’s wheels, showing the damage that they have experienced during the rover’s journey so far in Gale Crater.

At the time, I was unable to match any of the released images, taken on Sol 2732 (April 13, 2020), with the previous wheel image I have used to quickly gauge any new damage (see my July 9, 2019 report).

As it turns out, one of those images did match the earlier image. I simply failed to realize it. Today’s daily download of raw images from Curiosity included additional photos of the rover’s wheels, apparently also taken on Sol 2732 but not available until now. One of those images matches the earlier wheel image, and this time I spotted the match. A comparison is posted below, with my analysis.
» Read more

Rover update: Curiosity heads downhill

Curiosity's last look across the Greenheugh Pedimont
Click for higher resolution.

[For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater. For the updates in 2018 go here. For a full list of updates before February 8, 2018, go here.]

After finally reaching the top of the Greenheugh Pedimont (see both the March 4 and March 8, 2020 rover updates) and spending more than a month there, drilling one hole, getting samples, and taking a lot of photos, the Curiosity science team in the past week has finally sent the rover retreating back downhill, following the same route it used to climb uphill.

The panorama above was taken on April 10, 2020, and shows the last view looking south across that pedimont towards Mount Sharp, before that descent. As you can see, trying to traverse that terrain would have been very difficult, and probably very damaging to Curiosity’s wheels.
» Read more

Curiosity reaches highest point yet on Mars

Curiosity looking north across Gale Crater
Click for full resolution version.

Time for some more cool images! The panorama above, cropped and reduced to post here, was assembled from images taken by Curiosity on March 6, 2020 by its left navigation camera, just after it topped the slope and settled on the very rocky plateau of what the scientists have dubbed the Greenheugh Piedmont, the highest point on Mars that Curiosity has so far traveled. It looks north, across Gale Crater to its far rim, about thirty miles away. That rim rises about a mile higher than where Curiosity sits today.

To quote Michelle Minitti, the planetary geologist who wrote the update describing this achievement:

Kudos to our rover drivers for making it up the steep, sandy slope below the “Greenheugh pediment” (visible in the [right] side of the above image) and delivering us to a stretch of geology we had our eyes on even before we landed in Gale crater!

The panorama below is also assembled from photos taken by the left navigation camera, but this time it looks south, across the piedmont toward Mt. Sharp. Its view of the the piedmont’s very very rough terrain I think proves that once the scientists have gathered their data from this point, the rover will descend back down and resume its original route, circling the piedmont to skirt its southern edge where orbital data suggests the going will be smoother.
» Read more

Mars rover Update: March 4, 2020

Panorama looking south and uphill
Click for full resolution.

Curiosity

[For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater.

For the updates in 2018 go here. For a full list of updates before February 8, 2018, go here.]

Map of Curiosity's travels

Since my last rover update on January 13, 2020, Curiosity has finally moved on from the base of Western butte, where it spent more than a month drilling a hole and gathering a great deal of geological data. Rather than head downhill and around the plateau and back to its planned route (as indicated by the red line in the map to the right), the Curiosity science team decided to push upward and onto the Greenheugh Piedmont (as indicated by the yellow line).

They had always planned to reach the top of this plateau, but not for several years. First they were going to head east to study a recurring slope lineae (see my October 2019 update), an example of a dark streak that darkens and fades seasonally and could provide evidence of water seepage from below ground.

Instead, they decided the close proximity of the top of the piedmont and its geology was too tempting. The piedmont is apparently made up of a layer that is very structurally weak, and breaks up easily, as you can see by the panorama above. It also appears to sit on softer, more easily eroded material, which thus accentuates this break up. If you look at the left part of the panorama you can see what I mean. The piedmont layer there is the thin unbroken layer sitting on what looks like sand. As that sand erodes away the layer quickly breaks into small pieces, as shown in the rest of panorama.

Traveling on the piedmont will likely be difficult and threaten Curiosity’s wheels. I suspect this reality prompted them to choose to get to the top and obtain data now, rather than wait several more years of rough travel that might have made access to the piedmont difficult if not impossible.

They presently sit just below the top, and are studying their options before making that last push.
» Read more

Curiosity climbs a hill

Overview map of Curiosity's journey through sol 2643

[For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater.

For the updates in 2018 go here. For a full list of updates before February 8, 2018, go here.]

Since my last Curiosity update on November 6, 2019, the science team has sent the rover climbing up what they call Western Butte, the butte directly to the west of Central Butte and part of the slope/escarpment that separates the clay unit from the Greenheugh Piedmont and the sulfate unit above that.

The overview map to the right gives a sense of the journey. The thick yellow line indicates its route since it climbed up from the Murray Formation onto Vera Rubin Ridge in 2017. The thick red line indicates their planned route, which they have only vaguely been following since their arrival in the clay unit.

Below the fold are two panoramas that I created from a sequence of images taken by Curiosity’s left navigation camera from the high point on Western Butte, the first looking north across the crater floor to the Gale Crater rim approximately 30 miles away and indicated by the thin yellow lines on the overview map. The second looks south, up hill towards Mount Sharp, and is indicate by the thin red lines.
» Read more

Both methane and oxygen fluctuate in unison seasonally in Gale Crater

The uncertainty of science: According to a new science paper, data from Curiosity on Mars has now found that both methane and oxygen fluctuate in unison seasonally in Gale Crater.

From the paper’s abstract:

[T]he annual average composition in Gale Crater was measured as 95.1% carbon dioxide, 2.59% nitrogen, 1.94% argon, 0.161% oxygen, and 0.058% carbon monoxide. However, the abundances of some of these gases were observed to vary up to 40% throughout the year due to the seasonal cycle. Nitrogen and argon follow the pressure changes, but with a delay, indicating that transport of the atmosphere from pole to pole occurs on faster timescales than mixing of the components. Oxygen has been observed to show significant seasonal and year‐to‐year variability, suggesting an unknown atmospheric or surface process at work. These data can be used to better understand how the surface and atmosphere interact as we search for signs of habitability.

The data shows that the unexpected and so far unexplained seasonal oxygen fluctuation appears to track the same seasonal methane fluctuations. While biology could cause this signature, so could geological processes, though neither can produce these fluctuations easily.

Meanwhile, adding to the uncertainty were results from the two European orbiters, Mars Express and Trace Gas Orbiter. Both have failed to detect a June 19, 2019 dramatic spike in methane that had been measured by Curiosity.

Sightseeing Central Butte on Mars

Central Butte in foothills of Mt Sharp

Overview showing perspective of panorama

Curiosity has now roved to the very foot of Central Butte, where it has been taking close-up and panorama images of the butte and its geological layers. The panorama above was created from three Curiosity navigation images taken on Sol 2577 (November 6, 2019), here, here, and here.

The overview on the right, based on Curiosity’s position about ten sols ago slightly farther from the butte, still indicates roughly with the yellow lines the area photographed in this panorama. The dotted red line indicates Curiosity’s initial planned route.

Following that route Curiosity will eventually climb up onto the plateau beyond this butte, approaching that higher terrain farther to the west. Once they do, however, they will no longer have access to the geological layers below the surface. Central Butte gives them a window into those layers, which is why they are going to spend some time at this location, first by taking a few sols looking at the butte at this point, then circling around to study its back side.

Rover update: October 28, 2019

Summary: Curiosity finally on the move after several months drilling two adjacent holes in the clay unit. Yutu-2 continues roving west, has it now operates during its eleventh lunar day on the far side of the Moon.

For the updates in 2018 go here. For a full list of updates before February 8, 2018, go here.

Curiosity's present location in Gale Crater
Click for original full image.

Curiosity

For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater.

I have not done any of my regular rover updates since May 30, 2019 because it was simpler to do individual updates for both Curiosity and Yutu-2, the only working rovers presently on other worlds. (If things had gone well, which they did not, we would have had two other lunar rovers in the past six months, one from Israel and one from India, but both crashed during landing.)

However, since Curiosity is finally on the move after spending several months at one location, where it drilled two holes in the clay unit (the material from one used in a wet cup experiment to look for organic life) it is time to update my readers on where Curiosity is and where it is heading.

The first image above and to the right is an annotated overview of Curiosity’s present position, moving south to a line of buttes which scientists have determined delineates the transition from the clay unit to a new geological layer they have dubbed the Greenheugh Pedimont. The yellow lines indicate the area seen in the panorama below, created from two photographs (here and here) taken by the rover’s navigation camera.
» Read more

Curiosity takes selfie next to two of its most important drill holes

Curiosity and its most recent drill holes
Click for full image.

The Curiosity science team today released a beautiful mosaic of the rover, stitched from 57 different images. The photo at the right, cropped and reduced to post here, is the annotated version of that image. It shows the rover’s two most recent drill holes to the left. As the view looks away from Mount Sharp, you can see in the distance Vera Rubin Ridge, the floor of the crater, and its rim on the far horizon.

The two drill holes are significant because of the chemical experiment that Curiosity is subjecting the material from those holes.

The special chemistry experiment occurred on Sept. 24, 2019, after the rover placed the powderized sample from Glen Etive 2 into SAM. The portable lab contains 74 small cups used for testing samples. Most of the cups function as miniature ovens that heat the samples; SAM then “sniffs” the gases that bake off, looking for chemicals that hold clues about the Martian environment billions of years ago, when the planet was friendlier to microbial life.

But nine of SAM’s 74 cups are filled with solvents the rover can use for special “wet chemistry” experiments. These chemicals make it easier for SAM to detect certain carbon-based molecules important to the formation of life, called organic compounds.

Because there’s a limited number of wet-chemistry cups, the science team has been saving them for just the right conditions. In fact, the experiment at Glen Etive is only the second time Curiosity has performed wet chemistry since touching down on Mars in August 2012.

This time however was the first time they had used a wet chemistry cup on material from a drill hole. That they were able to do this at all is a testament to the brilliant innovative skills of the rover’s engineers. They had been holding off doing a wet chemistry analysis from drill hole material until they got to this point, but on the way the rover’s drill feed mechanism failed. It took more than a year of tests and experimentation before they figured out a way to bypass the feed mechanism by using the arm itself to push the drill bit into the ground. That rescue made possible the wet chemistry experiment that they initiated on September 24.

The results, which are eagerly awaited, won’t be available until next year, as it will take time for the scientists to analyze and publish their results.

Curiosity meanwhile has moved on, leaving this location where it had remained for several months to march in the past week southward back towards its long planned route up Mount Sharp.

The drying out of Mars

Edge of wash
The Murray formation as seen in 2017

A new paper based on data gathered by the rover Curiosity in 2017 when it was lower on the slopes of Mount Sharp, as well as data obtained more recently at higher elevations, has confirmed that the past Martian environment of Gale Crater was wetter, and that deeper lakes formed lower down, as one would expect.

In 2017 Curiosity was traveling through a geological layer dubbed the Murray formation. It has since climbed upward through the hematite formation forming a ridge the scientists dubbed Vera Rubin Ridge to reach the clay formation, where the rover presently sits. Above it lies the sulfate-bearing unit, where the terrain begins to be get steeper with many very dramatic geological formations.

Looking across the entirety of Curiosity’s journey, which began in 2012, the science team sees a cycle of wet to dry across long timescales on Mars. “As we climb Mount Sharp, we see an overall trend from a wet landscape to a drier one,” said Curiosity Project Scientist Ashwin Vasavada of NASA’s Jet Propulsion Laboratory in Pasadena, California. JPL leads the Mars Science Laboratory mission that Curiosity is a part of. “But that trend didn’t necessarily occur in a linear fashion. More likely, it was messy, including drier periods, like what we’re seeing at Sutton Island, followed by wetter periods, like what we’re seeing in the ‘clay-bearing unit’ that Curiosity is exploring today.”

Up until now, the rover has encountered lots of flat sediment layers that had been gently deposited at the bottom of a lake [the Murray Formation]. Team member Chris Fedo, who specializes in the study of sedimentary layers at the University of Tennessee, noted that Curiosity is currently running across large rock structures [Vera Rubin Ridge and the clay formation] that could have formed only in a higher-energy environment such as a windswept area or flowing streams.

Wind or flowing water piles sediment into layers that gradually incline. When they harden into rock, they become large structures similar to “Teal Ridge,” which Curiosity investigated this past summer [in the clay formation]. “Finding inclined layers represents a major change, where the landscape isn’t completely underwater anymore,” said Fedo. “We may have left the era of deep lakes behind.”

Curiosity has already spied more inclined layers in the distant sulfate-bearing unit. The science team plans to drive there in the next couple years and investigate its many rock structures. If they formed in drier conditions that persisted for a long period, that might mean that the clay-bearing unit represents an in-between stage – a gateway to a different era in Gale Crater’s watery history.

None of these results are really surprising. You would expect lakes in the flatter lower elevations and high-energy streams and flows in the steeper higher elevations. Confirming this geology however is a big deal, especially because they are beginning to map out in detail the nature of these geological processes on Mars, an alien world with a different make-up and gravity from Earth.

Below the fold is the Curiosity science teams overall map, released in May 2019, showing the rover’s future route up to that sulfate unit, with additional annotations by me and reduced to post here.
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Communications restored with Curiosity

The most recent Curiosity drill hole
Click for full resolution image.

With Mars moving out from behind the Sun yesterday, the Curiosity science team has successfully reestablished communications with the rover.

The focus of Curiosity’s activities since returning to operations after conjunction, now that Mars has safely moved out from behind the sun, is to finish up the analyses associated with the drilling campaign at “Glen Etive 1.”

The image to the right, cropped and reduced to post here, was among the first images downloaded from the rover once communications were reestablished. It was taken by a camera at the end of the robot arm that the scientists had positioned above the hole in order to get a close-up.

Before continuing up the mountain they now plan a second drill hole close-by, to better constrain the data at this location obtained from this first hole.

Rover update: May 30, 2019

Summary: Curiosity confirms clay in the clay unit. Yutu-2 begins its sixth day on the far side of the Moon. Three other rovers move towards completion and launch.

For the updates in 2018 go here. For a full list of updates before February 8, 2018, go here.

Clouds over Gale Crater
Clouds over Gale Crater

Curiosity

For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater.

Curiosity’s journey up the slopes of Mount Sharp in Gale Crater goes on! On the right is one of a number taken by the rover in the past week, showing water clouds drifting over Gale Crater.

These are likely water-ice clouds about 19 miles (31 kilometers) above the surface. They are also “noctilucent” clouds, meaning they are so high that they are still illuminated by the Sun, even when it’s night at Mars’ surface. Scientists can watch when light leaves the clouds and use this information to infer their altitude.

While these clouds teach us something about Martian weather, the big rover news this week was that the data obtained from the two drill holes taken in April show that the clay formation that Curiosity is presently traversing is definitely made of clay, and in fact the clay there has the highest concentration yet found by the rover.

This clay-enriched region, located on the side of lower Mount Sharp, stood out to NASA orbiters before Curiosity landed in 2012. Clay often forms in water, which is essential for life; Curiosity is exploring Mount Sharp to see if it had the conditions to support life billions of years ago. The rover’s mineralogy instrument, called CheMin (Chemistry and Mineralogy), provided the first analyses of rock samples drilled in the clay-bearing unit. CheMin also found very little hematite, an iron oxide mineral that was abundant just to the north, on Vera Rubin Ridge. [emphasis mine]

That two geological units adjacent to each other are so different is significant for geologists, because the difference points to two very different geological histories. The formation process for both the clay unit and Vera Rubin Ridge must have occurred at different times under very different conditions. Figuring out how that happened will be difficult, but once done it will tell us much about both Gale Crater and Mars itself.

With the success of their clay unit drilling campaign, the Curiosity science team has had the rover begin its trek back from the base of the cliff below Vera Rubin Ridge to its planned travel route up the mountain.

An updated description of that route was released by the Curiosity science team last week, while I was in Wales. Below is their image showing that route, with additional annotations by me and reduced to post here.
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Curiosity second drill hole in clay formation a success

two drill holes in clay formation
Click for full image.

The Curiosity science team has confirmed that their second drill hole in the clay formation that the rover is presently exploring was a success.

They have confirmed that enough material from the drill hole has been deposited in their chemical analysis hopper.

The image to the right, cropped and reduced to post here, shows both drill holes on the two different flat sections of bedrock near the top.

It seems that the science team wants to spend a lot of time in this location, as described in my last rover update. It is therefore unclear when they will move south to follow their long term travel plans.

Rover update: February 20, 2019

Summary: Curiosity in the clay unit valley. Opportunity’s long journey is over. Yutu-2 creeps to the northwest on the Moon’s far side.

For the overall context of Curiosity’s travels, see my March 2016 post, Pinpointing Curiosity’s location in Gale Crater.

For the updates in the past year go here. For a full list of updates before February 8, 2018, go here.

Curiosity

Curiosity's view to the east on Sol 2316
Click image for full resolution version

Overview of Curiosity's future travels
Click image for original image

Since my January 22, 2019 update, Curiosity finally drove down off of Vera Rubin Ridge into a valley between the ridge and the lower slopes of Mt Sharp. The Mars Reconnaissance Orbiter (MRO) overview on the right has been annotated by me to show the rover’s travels (shown by the yellow dotted line), with its proposed route indicated by the red dotted line. The yellow lines indicate approximately the terrain seen in the panorama above. The panorama was created from images taken on Sol 2016.

The valley that Curiosity is presently traversing is dubbed “the clay unit” or “the clay-bearing unit” by the geologists, based on its make-up determined from orbital data. So far they have found this terrain to be “some of the best driving terrain we’ve encountered in Gale Crater, with just some occasional sandy patches in the lee of small ridges.” Initially they had problems finding any rocks or pebbles large enough for the instruments to use for gathering geological data. For the past week or so, however, they have stopped at “bright exposure of rock” where some bedrock was visible, giving them much better material to work with.
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The base of Mt Sharp is less compacted than expected

The uncertainty of science: Using data from Curiosity in Gale Crater on Mars, scientists have found that the material making up the lower layers of Mount Sharp is less compacted that they would have expected.

Scientists still aren’t sure how this mountain grew inside of the crater, which has been a longstanding mystery.

One idea is that sediment once filled Gale Crater and was then worn away by millions of years of wind and erosion, excavating the mountain. However, if the crater had been filled to the brim, the material on the bottom, which now makes up the crater’s surface, would have been pressed down. But the new Science paper suggests Mount Sharp’s lower layers have much less compacted than this theory predicts, reigniting the debate about how full the crater once was.

“The lower levels of Mount Sharp are surprisingly porous,” said lead author Kevin Lewis of Johns Hopkins University. “We know the bottom layers of the mountain were buried over time. That compacts them, making them denser. But this finding suggests they weren’t buried by as much material as we thought.”

I can’t help wonder whether we don’t yet really understand the influence of Mars’ lower gravity on geology, and that might explain the porosity.

Planetary rover update: January 22, 2019

Summary: Curiosity begins journey off of Vera Rubin Ridge. Opportunity’s silence is now more than seven months long, with new dust storms arriving. Yutu-2 begins roving the Moon’s far side.

Before providing today’s update, I have decided to provide links to all the updates that have taken place since I provided a full list in my February 8, 2018 update. As I noted then, this allows my new readers to catch up and have a better understanding of where each rover is, where each is heading, and what fascinating things they have seen in the past few years.

These updates began when I decided to figure out the overall context of Curiosity’s travels, which resulted in my March 2016 post, Pinpointing Curiosity’s location in Gale Crater. Then, when Curiosity started to travel through the fascinating and rough Murray Buttes terrain in the summer of 2016, I stated to post regular updates. To understand the press releases from NASA on the rover’s discoveries it is really necessary to understand the larger picture, which is what these updates provide. Soon, I added Opportunity to the updates, with the larger context of its recent travels along the rim of Endeavour Crater explained in my May 15, 2017 rover update.

Now an update of what has happened since November!
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Gale Crater dunes: dry and volcanic in origin

Using data from orbit and from the rover Curiosity, scientists have determined that the material in the dunes in Gale Crater that Curiosity has visited are very dry and volcanic in origin.

This dryness is in contrast with the underlying ground, which shows evidence of water. The data also suggests that the material either came from multiple volcanic sources producing different compositions, or some of the sand was somehow changed at a later time.

In other words, the sand in the dunes came from elsewhere.

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